Japan continues to be rattled by aftershocks, but the biggest shock for the country now that the 8.9 quake is over and day has broken in Japan may be in assessing the damage from the monster trembler and the subsequent tsunami.

Hours after the buildings stopped shaking, fires still burned and Tokyo remained largely paralyzed with phone and train service halted -- though as Saturday wore on train service began to come back. Nuclear plants were disabled and thousands of people were urged to evacuate because of high radiation levels.

The official death toll from Friday's earthquake and tsunami stands at 413, while 784 people were missing and 1,128 were reported injured according to the Associated Press.

However, many observers feared the numbers of dead and injured would soar as searchers gained access to the hardest hit areas.

Between 200 to 300 bodies were seen in Sendai, the coastal region hit hardest by the quake, though damage to roads and fear of more tsunamis reportedly kept officials from getting at them.

Japanese government officials were telling local media they were certain the death toll would rise to more than 1,000.

Many in Tokyo spent the night in their cars trying to get home because the highways were all closed and cars clogged the city's streets. Store shelves were stripped bare by shoppers and thousands more spent the night in their offices.

In the Shibuya area in the heart of Tokyo, a bank was filled with sleeping people.

It was harder to assess damage outside the capital because of cut phone communications. Much of the town of Kesennuma near Miyagi, burned during the night with no apparent hope of being extinguished, public broadcaster NHK said.

Japan's coast guard was searching for 80 dock workers on a ship that was swept away from a shipyard in Miyagi.

President Obama called the tsunami "catastrophic" and said help was on the way. The United States has one aircraft carrier in Japan and another is on the way, and a ship is also en route to Marianas Islands for assistance, Obama said.

In addition, a USAID Disaster Assistance Response Team is assembling to go to Japan, and the Pentagon is sending some P-3 Orion maritime surveillance aircraft to support the Japanese government by providing aerial reconnaissance over quake-damaged areas.

"Disaster in the Pacific": Watch "World News" at 6:30 p.m. ET, a special edition of "20/20" at 10 p.m. ET and "Nightline" at 11:35 p.m. ET for special coverage of the Pacific earthquake and tsunami. CLICK HERE for more.

The earthquake, the fifth largest in recorded history and the largest ever to hit Japan, struck about 2:46 p.m. local time. It triggered a tsunami that unleashed a menacing stew of debris with objects as large as ships, cars and houses coursing over the countryside and into towns, crushing buildings and everything in its path. Eerily, fires burned in the watery mess as it flowed along.

Tokyo Comes to Stand Still After Tsunami Hits

So far, there are no reports of American fatalities in Japan, but anxious posts on Facebook by Americans living there reveal the devastation in the hard-hit Sendai area.

One woman affiliated with a missionary school in Sendai sent a Facebook message to friends and family saying she and all of the 40 member staff at the MeySen School are luckily safe.